Why is my cory catfish not moving?

i have a two week old 24l tropical fish tank community, with shoals of neons and danios, and an albino cory catfish. for the past day, my catfish has stopped moving around, even for food, and just lies on the gravel breathing normally. i don't know whether it's ill, or lonely, as i heard you're supposed to keep corys in small groups. i don't know whether its injured, as when it does swim it swims very close to the rocks and so swims a bit lopsided anyway. im going to the pet shop tonight to buy some fish stuff and i wondered if anyone could offer any advice as to what is wrong with my cory. any helpful ideas will be greatly appreciated, thank you :)
Answers:
Swimbladder is a disease which symptoms cause fish to become unable to swim correctly, your fish may exhibit swimming toward the bottom of your tank or bowl, then floating back up, swimming in circles or laying or floating on his side..
There are three main things according to the posts and articles I've read that can lead to swimbladder disease.

Constipation due to overfeeding
Bad water quality
Bacteria

Do a significant change when you suspect swimbladder disease and then follow this treatment. If you don't use aquarium salt this is a good addition to most tanks. The recommended dose is one teaspoon per gallon, or one tablespoon per five gallons. If you have never added salt and you are unsure; you may want to first acclimate him at only 1/2 tsp per gallon.
If this seems to be a frequent problem you may consider feeding less. Your water quality could indicate more frequent water changes.
FROM http://www.hv3.7h.com/swim%20bladder%20d.
Also, make sure your water is at the right temp (72-79) and provide something for him to hide under. Considering the number of fish in you tank aeration would be a good idea.
A IT IS A GOOD IDEA OF YOURS.I THINK IT IS SICK.It's playing dead.Well, if you're tank is 24 Liters, that's only 6 US gallons. Probably too small for the amount of fish you have. How many are there exactly? You're right, cories do best in groups of at least 3, but I wouldn't recommend that if the tank is that small. Your tank is new, so it's most likely not cycled. He might be stressed from the ammonia/nitrite levels in the tank. Read up on cycling a fish tank, just type it in the search box.

My partner had a Murry Cod and he ate a fish almost the size of himself, he just sat on the bottom and wouldnt eat for about 2 weeks while he digested his food.

maybe your catfish has eaten another fish??Catfish will eat just about anything, being a native.Catfish, unlike other fish, are able to breathe without moving. It is quite normal for catfish to spend some time lying on the bottom. However, it is not normal for it to hardly move at all. Importanly, do you have adequate plants in your tank? Albino corys need some shelter from aquarium lights. A plant like Giant Vallis will create shadows on the bottom of the tank for him to hide in. Also, what are you feeding? Normal flake food may not make it to the bottom of the tank so try a pellet catfish food, which will sink. Also, water quality is very important. Get nitrate testing kit and monitor your quality. Also, you should not have more inches of fish (not including fins) than litres in the tank. So you should not have more than 24 inches of fish. An airstone may help also, to provide extra aeration in the water. Corys do like to live in shoals, but then they do tend to jsut lie on the bottom in shoals.Catfish are bottom dwellers. It's normal behavior, and he is probably more active at night when you cannot see him and your light is off.once u see any cory swim with a flicker of "lop-sidedness", then it's only a matter of time the inevitable shall happen >> it is dying soon. Very hard to treat. Fruitless. Take it out soon so as not to infect your other fishes.waiting for the lights to change!
turn your light out you should then see it move. Related Questions and Answers ...